That's basically my question. I keep reading it here and that 3tech sells them. I'd be interested in the economy cam. Would I also need a +10 advance? How does it even work? Sorry for the n00b question, I just don't have that much experience with this in general.

I'm getting confused about what I'd need to improve economy on my car right now. It's a '99 Firefly all base with the 1L 3Cyl., so a G10 engine I think.

According to the report thread for the econo cams it boosts fuel economy by 15% or so. Is that for everybody?Otherwise I read other people use XFi cams and whatnot.. what's the difference as opposed to what 3tech offers?

XFI cams came with a slightly different shaped lobe and advance ground into the cam, I think 6°, maybe 8°. 3Tech economy cams are reground to a shape like the XFI cam, you can use an advance pulley to duplicate the needed advance. That alone is not going to give you a 15% increase, you also need a gear ratio change to go along with it to get the full benefit. Swapping your transmission for one out of a four cylinder car is the common method, but that's a pretty big jump, don't try it without the cam and advance pulley, plus an ignition advance (this part costs nothing) on a healthy engine.

_________________91 Pontiac Firefly Turbo10 Suzuki Kizashi

Alcohol, Tobacco, and FirearmsShould be the name of a convenience store, not a government agency

XFI cams came with a slightly different shaped lobe and advance ground into the cam, I think 6°, maybe 8°. 3Tech economy cams are reground to a shape like the XFI cam, you can use an advance pulley to duplicate the needed advance. That alone is not going to give you a 15% increase, you also need a gear ratio change to go along with it to get the full benefit. Swapping your transmission for one out of a four cylinder car is the common method, but that's a pretty big jump, don't try it without the cam and advance pulley, plus an ignition advance (this part costs nothing) on a healthy engine.

Thanks!But I have no real interest in swapping the entire tranny. So long as my 3 cyl. one will work, I'm good! However then, is it worth my time to get one of these sprockets or the 3tech cam without switching the tranny? I mean, will I see any difference like low end torque or fuel economy improvement? Maybe not 15% but a worthwhile % instead?

Wherever I read, it seems either or both together always seem to improve fuel economy. I guess I'd just like to improve mine.

I put that together last year after typing out the same answers to the same questions day after day

Anything I should add?

OK. I'll bite... Since Copper Top was bored out during the rebuild, it has never idled without having a mild, intermittent missing. I don't believe the head was shaved to increase compression. It Just has your econo grind cam and the +6 sprocket. Annoying, but I have just come to accept it as my fate... (viewtopic.php?f=22&t=39843&start=0) ...although I've been wondering over the winter if the econo cam is simply restricting the air/fuel intake too much for a bored out block.

Anyway, with a greater volume of air trying to be sucked into the bored out cylinders, would you have any alternate cam/sprocket recommendations for maximizing fuel economy vs. performance?

Sometime in the (hopefully) near future I'll try different combinations of econo, regular, and performance cams with regular, +6, and +10 cam sprockets to see how they affect it's idling, compression, and mpg numbers.I first have to arrange a re-roof of our cabin and carport conversion to a garage before I'll be able to get to that.It's all about priorities...

Alrighty... so I figured I'd bump this question because I have a REALLY stupid question in regard to the install of the +10 sprocket I did. Been way too busy with stuff to do it but I hope I can do it this weekend or next week. Basically, the install looks straightforward BUT... once I get everything in place, I read that I should turn the engine by hand to see that everything is alright... uh.. well, how do I turn the engine by hand?

Sometime in the (hopefully) near future I'll try different combinations of econo, regular, and performance cams with regular, +6, and +10 cam sprockets to see how they affect it's idling, compression, and mpg numbers.I first have to arrange a re-roof of our cabin and carport conversion to a garage before I'll be able to get to that.It's all about priorities...

Priorities and niggling concerns: I have 3 cyl. 5 speed Geo Metros and they all get 50 mpg+ VERY stock, 35 lbs in tires, good, complete tunes, Pennzoil Synchromesh and some graphite in the transmissions, normal accoutrements, rear view mirrors etc.

Why bother spending money altering everything? You will NEVER get your money back in economy.

If you count the teeth on the cam... Take 360 and devide that by the number of teeth... then you will find something rather interesting...

If you simply skip a toot on the cam gear, you can advace or retard by 9 degrees.

Sure it's not the 10 degrees offered by the professionals, but if you are a good old DIYer, then this is pleanty to play with!

Change the cam by 9 degrees, then just make sure and change your distibuter timming back to compensate.

Maybe my first ever post will help in this subject?? I've been reading these posts for maybe 2 months (since I bought my first compact, a '95 suzuki swift). And this is the first time I had anything of any possible value to express to the rest of this WONDERFUL community. Thanks for all the crazy and informative info ladies and gentlemen!!!

well, i kept reading... actually i just read it all again. So there is regular, advace by 6 degrees and advace by 10 degrees wich are mentioned in the post... All of these require bying a new cam gear, right? Swithcing it out and whatnot... So why is skipping one of the 40 teeth to make it 9 degrees not an option???

Hi there peoploids.....Yes it can be very hard to recoup your cost while doing things to save. I look at it this way:One lump sum is forgotten soon enough (it only hurts for a little time as they say in collector's circle) but continuous economy at the pump brings us a smile everytime.

Not only did I install the economy cam, I also installed the final drive pair unit from a 4 cylinder engine. If I recall I only had my machinist skim .020 from the face of the flat gear and it was a perfect fit. The 3cyl. unit stays in the car. Lots of fine reading on this on metrompg and ecomodder.

So happy am I with the result, that I am having this small 1994 black coupe repainted to perfection as I write. Everything is dismantled, folds are opened, sanded, repainted; moldings, doors off..... hanging in the paint room...etc...Is it worth it on a car with minimal value? In the words from the philosopher who hails from Alaska: YOU BETCHA!

Yeah, it's 9 degrees divided by 2 because the cam rotates at half the speed of the engine. So....it's 4.5 degrees. So jump two teeth if you want 9 cheap degrees, and only one if you want 4.5. Simple really. However, the machined sprockets would take all the guess work out of it. And make sure you are moving it in the proper direction. Advancing the cam will move your powerband lower in the rpm range, and retarding it moves it up the range. As a rule of thumb, anything more than 9-10 degrees and you need to choose a cam that is better suited to your application.

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